Method of optical particle counting for water mixed lubricant

Abstract

Solid particles combined with a water contaminated oil sample are counted by an optical particle counter. The contaminated oil sample is mixed at a substantially 1:1 ratio with a water masking solvent comprising about one part isopropanol and about three parts toluene. The oil and solvent mixture is passed through a transparent viewing volume between a light source and a light detector for detection and counting of oil suspended solid particles.

We claim: 
     
       1. A method of determining the quantity of free immiscible fluid dispersed as droplet particles in the presence of oil having solid particles suspended therein, said method comprising the steps of optically determining the combined particle size distribution of substantially all particles in a sample of said oil, mixing said oil sample with a masking fluid that is soluble with said oil and said immiscible fluid, optically determining the size distribution of substantially all particles remaining in said oil sample after mixing with said masking fluid, and deducting the remaining particle size distribution from the combined particle size distribution to conclude a quantity of free immiscible fluid initially present in said oil sample. 
     
     
       2. A method as described by claim 1 wherein said masking fluid comprises about one part isopropanol and about three parts toluene. 
     
     
       3. A method as described by claim 2 wherein about one part of said oil sample is mixed with about one part of said masking fluid. 
     
     
       4. A method as described by claim 1, wherein the particle size distribution in said sample is determined by laser emission means. 
     
     
       5. A method of operating a photo responsive particle counter having a fluid flow channel through a view volume, a view area of said view volume that is substantially transparent between opposite sides of said view area, light emission means on one side of said view area, light detection means on an opposite side of said view area and particle counting means responsive to signals from said light detection means signifying the passage of light obstructing particles through said view volume, said method comprising the steps of preparing a solvent having about one part isopropanol and about three parts toluene, preparing a test sample by mixing about one part of said solvent with about one part of a test oil having light obstructing particles and substantially immiscible fluids mixed therewith and flowing a measured portion of said test sample through said view volume and counting the number of light obstructing particles mixed therewith. 
     
     
       6. A method of operating a particle counter as described by claim 5 wherein a particle count respective to said solvent is obtained independently of said test oil. 
     
     
       7. A method of operating a particle counter as described by claim 5 wherein the particle count from said test sample is adjusted according to the particle count of said solvent. 
     
     
       8. A method of operating a particle counter as described by claim 5 wherein said light emission means is a laser means. 
     
     
       9. A method of counting substantially solid particulates suspended in a contaminated oil medium having substantially immiscible fluids mixed with solid particles, said method comprising the steps of preparing a solvent comprising about one part isopropanol and about three parts toluene, mixing a test fluid with about one part solvent and about one part of said contaminated oil medium, flowing a predetermined portion of said test fluid through a substantially transparent view volume, and optically counting the number of substantially solid particulates in the predetermined portion of said test fluid. 
     
     
       10. A method as described by claim 9 wherein said one part solvent is caused to flow through said transparent view volume independently of said contaminated oil medium while the number of substantially solid particulates in said solvent is optically counted. 
     
     
       11. A method as described by claim 10 wherein the number of particulates counted from said portion of test fluid is adjusted according to the number of solid particulates counted in said solvent. 
     
     
       12. A method as described by claim 9 wherein a laser light source is directed through said view volume while said test fluid flows therethrough for optically counting said solid particulates. 
     
     
       13. A method of operating a photo responsive particle counter having a fluid flow channel through a view volume, a view area of said view volume that is substantially transparent between opposite sides of said view area, light emission means on one side of said view area, light detection means on an opposite side of said view area and particle counting means responsive to signals from said light detection means signifying the passage of light obstructing particles through said view volume, said method comprising the steps of: preparing a test sample by mixing test oil with a masking solvent, said test oil having dispersed therein light obstructing particles and at least one contamination fluid that is substantially immiscible with said oil, said masking solvent being miscible with said oil and said contamination fluid; and, flowing a measured portion of said test sample through said view volume and counting the number of light obstructing particles mixed therewith. 
     
     
       14. A method of operating a particle counter as described by claim 13 wherein a particle count respective to said solvent is obtained independently of said test oil. 
     
     
       15. A method of operating a particle counter as described by claim 14 wherein the particle count from said test sample is adjusted according to the particle count of said solvent. 
     
     
       16. A method of operating a particle counter as described by claim 13 wherein said light emission means is a laser means. 
     
     
       17. A method of operating a photo responsive particle counter having a fluid flow channel through a view volume, light emission means, light detection means and particle counting means responsive to signals from said light detection means signifying the passage of light obstructing particles through said view volume, said method comprising the steps of: preparing a solvent having about one part isopropanol and about three parts toluene; preparing a count of light obstructing particles dispersed within said solvent; preparing a test sample by mixing about one part of said solvent with about one part of a test oil having light obstructing particles and fluids that are oil immiscible mixed therewith; and, flowing a measured portion of said test sample through said view volume and counting the number of light obstructing particles mixed therewith. 
     
     
       18. A method of operating a particle counter as described by claim 17 wherein the particle count from said test sample is adjusted according to the particle count of said solvent. 
     
     
       19. A method of operating a particle counter as described by claim 17 wherein said light emission means is a laser means. 
     
     
       20. A method of counting substantially solid particulates suspended in a contaminated oil medium having substantially immiscible fluids mixed with solid particles, said method comprising the steps of: preparing a solvent comprising about one part isopropanol and about three parts toluene; flowing said solvent through a substantially transparent view volume while the number of substantially solid particles disposed within said solvent is optically counted; mixing a test fluid with about one part of said solvent and about one part of said contaminated oil medium; flowing a predetermined portion of said test fluid through said view volume; and, optically counting the number of substantially solid particles in said predetermined portion of said test fluid.   
     
     
       21. A method as described by claim 20 wherein the number of particles counted from said portion of test fluid is adjusted according to the number of solid particles counted in said solvent. 
     
     
       22. A method as described by claim 20 wherein a laser light source is directed through said view volume while said test fluid flows therethrough for optically counting said solid particles. 
     
     
       23. A method of operating a photo responsive particle counter having a fluid flow channel through a view volume, a view area of said view volume that is substantially transparent between opposite sides of said view area, light emission means on one side of said view area, light detection means on an opposite side of said view area and particle counting means responsive to signals from said light detection means signifying the passage of light obstructing particles through said view volume, said method comprising the steps of: preparing a solvent with known particle count data;   preparing a test sample by mixing said solvent with a known quantity of test oil having light obstructing particles mixed therewith;   flowing a measured portion of said test sample through said view volume; and   counting the number of light obstructing particles mixed therewith.   
     
     
       24. A method of operating a particle counter as described by claim 23 wherein said light emission means is a laser means.